Process for the manufacture of fused cement and apparatus therefor



Jan. 25, 1927. 1,615,260

G. DUMAS PROCESS FOR THE MANUFACTURE OF FUSED CEMENT AND APPARATUSTHEREFOR.

Filed Jan. 15, 1924 "gm? Yang?- Patented Jan. 25,1927.

UNITED STATES PATENT OFFICE.

GEORGES DUHAS, OI VIVIERS, FRANCE, ASSIGNOR TO THE SOCIETE ANONYME DESCHAUX ET CIMENTS DE LAFARGE ET DU TEIL, OF VIVIERS, ABDEOEE, FRANCE,

A CORPORATION OF FRANCE.

PROCESS FOR THE MANUFACTURE OF FUSED CEMENT AND APPARATUS THEREFOR.

Application filed January 15, 1924, Serial No. 686,481, and in FranceSeptember 29, 1923.

The subject of this invention is a'process and an apparatus intended forproducing cement by fusion. It is particularly applicable to themanufacture of .aluminous cement, which it produces b continuous workingwith an economic pro action which the processes ordinarily employedcannot touch.

The invention rests on the rational utilization of a type of furnacewhich in itself is known but which is slightly modified and supplementedby auxiliary apparatus making continuous working possible. It is afurnace having a hearth of suitable shape heated by pulverized coal suchfor example as the reverberatory furnace generally used in metallurgyfor intermittent operations consisting in treating integrally a bed infusion before drawing and proceeding to a new charge.

In the application of this furnace to the manufacture of fused cementthe operation is carried out in accordance with the invention in acontinuous manner by adding to the furnace a charging arrangement whichensures uninterrupted ceding.

- This continuous working can naturally not be carried out except on thecondition of causin by a method of rational heating, a rapid fusion ofthemixture of materials to be treated in proportion as they reach thehearth of the furnace. For this purpose" the heating is effected by theinjection of a gaseous, liquid or pulverized fuel which is burnt in thechamber of the furnace where the intense heat su plied by the flame andradiated by the arch causes the rapid fusion which is desired.

The accompanying drawing shows by way of example and in a die rammaticform the aggregate of an instal ation intended for putting the processinto ractice.

The combustion cham er 1 of carefully calculated dimensions comprisesparticularl a hearth 2 surmounted b an arch 3 bot constructed ofsuitable re ractory materials. -represents in section one or morecombined tuyeres for the injection of the supporter of combustion and ofthe fuel, which, in the exam le in question, is ulverized coal collected1n the hopper 5 and ed by the regulating screw 6 into the delivery pipe7 of the fan 8 which blows it into the furnace through the tuyeres 4.The material to be fused, heated by the burnt gases which escape fromthe furnace, is continually poured on to the hearth 2 through theopening 9 either by gravity or by any mechanical means. A tapping hole10 is arranged in the hearth 2 at a suitable height for running off thefused cement. Finally, inspection holes 11 and a door 12 suitablylocated for inspecting and poking allow of the fusion being watched andmodified at every moment which is a valuable advantage not possessed bythe processes hitherto in use.

In an oven of the type described the process has been applied withsuccess and in a continuous manner. The mixture to be introduced in theoven was made up of .100 kilogs. of bauxite for a 110 kilo s. of limestone, each of. them was separate y crushed before mixing. The feedingwas continuous, and the speed of feeding was controlled in order tomaintain in the oven a mound of conical shape of uniform height. Thewhole of the char e was transformed into fused cement, whic flowed in acontinuous manner. The amount of fused cement produced in 24 hours wasof 16 tons, the expenditure of pulverized coal was below 350 kilogs. perton of fused cement. The temperature during the working was, at theinterior of the oven, of about 1500 centigrade. Other advantages resultfrom the continuous working of the reverberatory furnace,

The scope of the invention will not be departed from by modifying theaccessory apparatus provided that the essential characteristicsconstituted by a reverberatory furnace are maintainedfsaid furnace beingfed by an automatic charging apparatus working continuously.

I claim:

1. Process of obtaining fused cement in reverberatory furnaces,particularly aluminous cement, which comprises continuously feedingcement forming materials on to the hearth of a reverberatory furnace,from a substantial distance thereabove, melting said materials byimpingin burning fuel thereon, and allowing the fused cement to flowaway.

2. Process of obtaining fused cement in reverberatory furnaces,particularly aluminous cement, whlch comprises continuously feedingcement forming materials on to the hearth of a reverberatory furnacefrom a substantial distance thereabove, melting said materials byimpinging burning fuel thereon, maintaining said fused cement underexposure of the heat produced by the burning fuel and allowing it toflow away. y

In testimony whereof I hereunto afiix my signature. I

GEORGES DUMAS. [n 5.

